For the longest time, the 160×600 ads have been our lowest CPM ads/worst ROI ads and I couldn’t figure out why. There’s only one 160×600 on the page and it’s featured in the user messages, which is has a ton of volume! Anyway, so I discovered that the 160×600 is placed in the MIDDLE of the message. This is problematic because if the message is too long, this pushes the 160×600’s below the fold and thus, decreases performance.
Here’s what I mean:
So, the fix is basically going to anchor the 160×600 in a set spot regardless of how many messages someone gets or how long those messages are. By keeping the ad above fold, you should see an increase in performance on 160×600’s across the board.
In the meantime, spend some time making 160×600’s as this should be fixed by next week. And if you get in quick, the CPM’s are SUPER low so ROI will be SUPER high 🙂